Armando Hasudungan
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Protected: Congenital Heart Defect

by Armando Faigl

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Overview

Overview Congenital heart disease (CHD) is the most common congenital disorder in newborns.

Classification

  • Acyanotic and Cyanotic
  • Pulmonary blood flow
    • Increased
    • Decreased
    • Normal
Cyanotic (T’s) Acynotic (D’s)
Tetralogy of Fallot ASD
Transposition of the great vessles VSD
Tricuspid atresia AVSD
Truncus arteriosus Patent Ductus Arteriosus
Other: Pulmonary stenosis, Aortic stenosis, Coarctation of the aorta

Epidemiology

  • One-third to three-quarters of children have an innocent murmur noted at some time between age 1 and 14 years, the most frequent of which is an innocent Still’s murmur

Clinical Manifestation In infants, feeding difficulties may be the first sign of congestive heart failure

Cardiovascular

  • Poor feeding
  • Cyanosis/pallor
  • Clubbing
  • Murmur
  • Palpitation
  • Dizziness
  • Hepatomegaly

Constitutional

  • Excessive, unexplained irritability
  • Excessive sweating
  • Poor weight gain
  • Decreased activity or sleeping (easily fatigued)
  • Delayed developmental milestones motor
  • Poor exercise intolerance

Respiratory

  • Chronic cough – pulmonary vascular congestion
  • Dyspnoea on exertion
  • Wheezing – pulmonary congestion

Differential Diagnosis – innocent murmur’s

Remember The most common innocent murmur is a Still murmur
  • Aortic Systolic murmur
  • Still murmur
  • Venous hum

Investigations

  • ECG
    • Arrythmias
  • Chest X-ray
  • Echocardiogram
    • 16-20weeks gestation
    • After delivery
  • Cardiac catheterization

 

Foetal cardiac anatomy and physiology

Embryology

Foetal Circulation

Atrial Septal Defect

Overview

  • Left to Right shunt
  • Right atrium and right ventricle enlargement
  • Patients can present with atrial fibrillation
  • Pulmonary hypertension (late stage)
  • 4 different types
    • Ostium Primum
    • Ostium secundum (most common – 75%)
    • Unroofed coronary sinus defect
    • Sinus venosus defect
  • Patent foramen ovale (~20-25% of population)
    • Not a true ASD
    • Embolic phenomenon (venous origin bypasses lung)

Clinical Presentation

  • Child and adult are usually asymptomatic
    • Mid-systolic murmur (pulmonary valve)
    • Congestive heart failure in large defects
  • Adults:
    • Mid-systolic murmur (pulmonary valve)
    • Palpitations (AF)
    • Paradoxical embolus
    • Cerebral abscess

Investigations

  • Echocardiogram
    • location and type of ASD

Pathophysiology

  • Pressure normally greater in left side of heart
  • ASD causes left to right shunt → right atrial hypertrophy → ↑blood flow to right ventricle (right ventricular hypertophy) → ↑pulmonary blood flow

Eisenmenger Syndrome (Cyanosis)

  • ↑Pulmonary blood flow from sheer stress/circumferential stretch → Endothelial dysfunction and vascular remodelling → ↑pulmonary vascular resistance (pulmonary hypertension) → ↑pressure on the right side of heart → right to left shunt
Pulmonary hypertension is present when mean pulmonary artery pressure exceeds 25mm Hg at rest or 30 mm Hg with exercise. ECG findings include: RVH or strain, RAD, p-pulmonale, tall R waves in V1.

Ventral Septal Defect

Overview Most common congenital heart defect. It occurs in almost 50 percent of all patients with congenital heart disease.

Risk factors

  • Family history
  • Trisomy 21
  • Maternal
  • Alcohol

Important features of VSD

  • Size of defect – small or large
  • Pulmonary vascular resistance
  • Location type
Remember 75% of small defects undergo spontaneous closure within the first two years of life. Moderate VSD may close overtime. Large rarely close and require surgery

Clinical Presentation

  • Small defect – holosystolic murmur
  • Moderate large defect over time
    • Failure to thrive
    • Tachypnoea, dyspnoea
    • Feeding difficulties
    • Recurrent pulmonary infections
    • Endocarditis risk
    • Pansystolic murmur (Tricuspid area) – no radiation
    • Thrill around Tricuspid area
    • Loud P2
    • Cardiomegaly
Causes of Pansystolic mumurs
Mitral regurgitation
Ventricular septal defect
Tricuspid regurgitation

Pathophysiology of VSD

  • Pressure normally greater in left side of heart
  • VSD causes left-to-right shunt → ↑pressure in right ventricle → right ventricular hypertophy → ↑pulmonary blood flow

Eisenmenger Syndrome (Cyanosis)

  • ↑Pulmonary blood flow from sheer stress/circumferential stretch → Endothelial dysfunction and vascular remodelling → ↑pulmonary vascular resistance (pulmonary hypertension) → ↑pressure on the right side of heart → right to left shunt

Investigations and diagnosis

  • Echocardiogram (diagnostic)
  • Chest x-ray – changes of left-to-right shunt

Management

  • Surveillance (small VSD)
    • Cardiologist – echocardiograms/murmur
    • Immunizations
    • Monitoring of growth parameters
    • Monitoring symptoms of heart failure
  • Nutritional support – ↑calorie intake
  • Medical management – heart failure
    • Diuretics
    • +/- ionotropes
  • Surgical – for symptomatic moderate/large VSD
    • Direct patch closure of VSD

Complications

  • Endocarditis
  • Aortic regurgitation
  • Aortic stenosis
  • Congestive heart failure

Patent Ductus Arteriosus

Overview Normally ductus arteriosus closes and become ligamentum arteriosus. Patent ductus arteriosss is where the ductus arteriosus persists post partum for more than 3months. Patent ductus arteriosus creates a Left to right shunt. This occurs in 1 in 2000 live births.

Anatomy

The ductus arteriosus closes in approximately 90 percent of full-term neonates by 48 hours of age. Prolonged patency of the ductus arteriosus occurs in premature infants and those born at altitude

Risk Factors

  • Maternal rubella
  • High altitude (oxygen tension)
  • Prematurity
  • Female gender

Clinical presentation

  • Continous murmur around pulmonary valve

Management

  • Spontaneous closure (unlikely after 3 months)
  • Pharmacological ductal closure in premature babes: indomethacin/ibuprofen
  • Antibiotic prophylaxis for endocarditis risk
  • Device/surgical closure

Coarctation of the Aorta

Overview A stricture is present in the aorta which leads to restricted blood flow to the lower part of circulation. BP in head and UL’s is high, whilst that in the LL’s is low. Heart failure may develop Surgical repair is needed in most cases.

Clinical presentation

  • Weak femoral and lower limb pulses
  • Radial femoral delay
  • Bounding pulses in arms and carotids
  • Difference in left and right arm blood pressure (suggests subclavian coarctation
  • Hypertension
  • Pink upper body and cyanotic lower body (paediatrics mainly)
Remember Coarctation should be suspected in an asymptomatic child with hypertension

Investigations

  • Chest X-ray
  • ECG
  • Echocardiogram (gold standard)

Management

  • Neonates – PGE1
  • Surgery for significant coarctation
  • Adults – treat heart failure and hypertension, followed by surgery

Complications

  • Cerebrovascular disease
  • Systemic hypertension
  • Endocarditis
  • Aortic aneurysms

 

Stenotic congenital heart defect

Overview Aortic valve is thickened and narrowed leading to
development of abnormally high pressure in LV. LV becomes
hypertrophied. Correction with baloon valvuloplasty or surgery.

Pulmonary stenosis Pulmonary valve is thickened and narrowed leading to development of abnormally high pressure in RV. RV becomes hypertrophied If severe, treated with balloon catheter to dilate narrowing.

Tetralogy of Fallot

Overview The most common cyanotic congenital cardiac defect. In 1888, Etienne-Louis Arthur Fallot described four cyanotic patients with four similar anatomic features

4 anatomical features

  • Right ventricular hypertrophy
  • Pulmonary stenosis
  • Ventral septal defect
  • Aorta overriding the ventricular septum
Side Note there are a number of associated anatomical features associated with TOF including right aortic arch, left anterior descending from the right coronary artery, patent ductus arteriosus.

Pathophysiology

  • Largely dependant on right ventricular outflow obstruction
  • VSD → Aortic arch overriding the defect (aorta now pointing more to the right then left allowing blood from right ventricle to enter) → Left to right shunt (acynotic)
  • Left to right shunt→ Right ventricular hypertrophy → ↑pulmonary pressure causing pulmonary valve stenosis → ↑Right ventricular hypertrophy → Right to left shunt (cynotic)
  • “Tet spells” – Periods of increased oxygen demand/ultilisatio. Near occlusion of the right ventricular outflow tract with profound cyanosis.
Side note Children with cyanotic congential heart disease often squat. This kinks the femoral artery increasing peripheral resistance. This in turn increases left-sided ventricular resistance which lessens the burden of right-eft shunt.

Clinical presentation – depends on degree of right ventricular outflow obstruction

  • May be asymptomatic until hypercyanotic (tet) spells.
    • Hypercapneia
    • Agitation

Clinical Examination

  • Cyanosis
  • Harsh ejection systolic murmur (Pulmonary valve) stenosis)
  • Systolic thrill (Pulmonary valve)
  • Holosystolic murmur (Tricuspid area from ventricle septal defect)
  • Clubbing of nail beds

Diagnosis

  • Echocardiogram with dopller
  • ECG
    • Right ventricular hypertrophy
Remember ECG findings of right ventricular hypertrophy include: p-pulmonale (Right atrium), tall R waves in V1, upright T wave in V1 and marked right axis deviation
  • Chest X-ray – Boot shaped heart, unturned apex and a concave main pulmonary artery segment
  • Cardiac catheterisation to further delineate structural abnormalities.

Management – surgical

  • VSD closure with patch
  • Enlargement of pulmonary artery
  • Palliative procedure for symptom relief
    • Shunts – subclavian artery to the ipsilateral pulmonary artery

Tricuspid atresia

Transposition of the great arteries

Eisenmenger Syndrome

Overview Eisenmenger syndrome is the triad of congenital systemic-to-pulmonary cardiovascular communication, pulmonary arterial disease causing severe pulmonary hypertension, and cyanosis

Diagnosis

  • Presence of congenital heart disease
  • Exclusion of other causes of pulmonary hypertension

Clinical findings

  • Congenital heart defect
  • Central cyanosis
  • Digital clubbing